<?php
class code{
    /**
    * 功能和js unescape函数，解码经过escape编码过的数据
    * @param $str
    */ 
    public static function unescape($str) 
    { 
        $ret = '';
        $len = strlen($str);
        for ($i = 0; $i < $len; $i ++) 
        { 
            if ($str[$i] == '%' && $str[$i + 1] == 'u') 
            { 
                $val = hexdec(substr($str, $i + 2, 4));
                if ($val < 0x7f) 
                    $ret .= chr($val);
                else 
                    if ($val < 0x800) 
                        $ret .= chr(0xc0 | ($val >> 6)) .
                         chr(0x80 | ($val & 0x3f));
                    else 
                        $ret .= chr(0xe0 | ($val >> 12)) .
                         chr(0x80 | (($val >> 6) & 0x3f)) .
                         chr(0x80 | ($val & 0x3f));
                $i += 5;
            } else 
                if ($str[$i] == '%') 
                { 
                    $ret .= urldecode(substr($str, $i, 3));
                    $i += 2;
                } else 
                    $ret .= $str[$i];
        } 
        return $ret;
    } 
    /**
    * 功能是js escape php 实现
    * @param $string           the sting want to be escaped
    * @param $in_encoding      
    * @param $out_encoding     
    */ 
    public static function escape($string, $in_encoding = 'UTF-8',$out_encoding = 'UCS-2') { 
        $return = '';
        if (function_exists('mb_get_info')) { 
            for($x = 0; $x < mb_strlen ( $string, $in_encoding ); $x ++) { 
                $str = mb_substr ( $string, $x, 1, $in_encoding );
                if (strlen ( $str ) > 1) { // 多字节字符
                    $return .= '%u' . strtoupper ( bin2hex ( mb_convert_encoding ( $str, $out_encoding, $in_encoding ) ) );
                } else { 
                    $return .= '%' . strtoupper ( bin2hex ( $str ) );
                } 
            } 
        } 
        return $return;
    }
}